An exercise ball is a large, spherical, resilient ball that can be used for a variety of exercises. These balls are also commonly referred to as a “Swiss ball”, “Swiss exercise ball”, “stability ball” or a “pilates ball.” The ball is often inflatable, made of vinyl or plastic. Alternatively, it may be made of a solid material such as foam rubber. The balls typically have a diameter ranging from 45 cm. to 75 cm. in 10 cm. increments. A user will choose a ball based upon their height, with a user of smaller stature choosing a ball having a smaller diameter. For instance, a person with a height in the range of 5′3″ to 5′8″ would be matched to a ball with a 55 cm. diameter. Persons having a height exceeding 6′3″ would be matched to a ball having a 75 cm. diameter.
Exercise balls were originally used for therapeutic exercises, but have been more widely adopted in recent years to develop a user's flexibility, balance and strength, including the strength of seldom used stabilizer muscles. Exercise balls are typically used on the surface of a floor, with some portion of the weight of the user coming to rest upon the ball, thereby causing a deformation of the ball as it is pressed between the user and the floor. The resultant deformation adds a limited amount of resistance to the exercise. Used in this manner, the ball adds an element of instability to the exercise. This instability would not normally be experienced by a user with the associated exercise in the absence of the ball. Efforts by the user to counteract this instability and remain balanced on the ball allow the user to more fully exercise the body. One key cause of this instability is that the ball is not secured in any manner, other than by the weight of the user. Consequently, the ball is free to travel in any two dimensional direction by means of rotation across the horizontal plane created by the underlying floor.
The inherent characteristics of exercise balls have led to the recognition of numerous therapeutic uses for them. Due in part to these uses and characteristics, exercise balls have been incorporated into a number of exercise devices and other articles. U.S. Pat. No. 5,810,700 to Orcutt discloses an exercise apparatus utilizing a resilient ball and having a flexible strap assembly surrounding the ball. The flexible strap assembly coupled to the ball provides resistance for performing exercises. The resilient ball is designed to be used by a user in a seated position atop the ball, or otherwise with the user resting a portion of his or her body on the resilient ball, while pulling the resistance member in an elongation direction. The strap assembly includes first and second straps adapted to surround and couple to the resilient ball. A loop formed from one of the straps receives the resistance member. While providing additional exercises for use with an exercise ball, this device does not address the inherent instability of exercise balls.
U.S. Pat. No. 6,309,331 B1 to Raymond discloses an abdominal exerciser device utilizing a resilient rubber ball in contact with a plurality of ball bearings across the lower half of the ball. The ball is mounted inside a semi-spherical cavity that roughly corresponds in height to the lower half of the ball. Thus, a self-standing casing is formed to support the ball while allowing the rubber ball a free-rolling action when applied against a body part such as the abdominal, waist and/or hips effectively pressuring and massaging the muscles of the body part. It is further taught that one or more casings may also be mounted on absorbing materials, which is further mounted onto a rigid frame structure adapted to support a user. U.S. Pat. No. 6,669,611 B2, also to Raymond, discloses a similar abdominal exerciser.
U.S. Pat. No. 6,746,372 B2 to Hsu discloses an exercising ball holder for fixing an exercising ball. The holder is a concave device that cups the lower portion of an exercise ball. The holder further includes a base structure having multiple extension arms and at least one elastic cord attached thereto. The base seat is formed with a rest depression. A lower end of the exercising ball is rested and located in the depression preventing the ball from easily rolling out in response to directly downward pressure. The ball is free to be lifted out of the device and may be dislodged by forces applied from a side. The multiple extension arms extend outwardly from beneath the holder and have a fixing loop section at their respective ends for affixing the elastic cords. The elastic cords have handles at the ends opposite to where they affix to the base. The elastic cords are thus adapted to function as resistance members to be grasped by the hand of a user.
Other patents disclosing chairs or exercise devices incorporating exercise ball-like objects, or variations thereof, include U.S. Pat. No. 4,126,326 to Phillips, U.S. Pat. No. 5,690,389 to Ekman et al., U.S. Pat. No. 5,833,587 to Strong et al., U.S. Pat. No. 6,461,284 B1 to Francavilla, U.S. Pat. No. 6,478,721 to Hunter and U.S. Pat. No. 6,702,726 to Lin.
As discussed above, exercise balls are useful tools for exercise, but suffer from a number of limitations as a result of their ability to roll in any direction along the horizontal plane. Exercise balls are inherently unstable. Often this instability is not desired by the user. This instability often makes it more difficult to isolate the desired muscle group or groups intended by a particular exercise motion. The feeling of instability can be unnerving to inexperienced users and may even lead to injury due to loss of balance or when otherwise used improperly. This is especially true if the user suffers from a physical ailment or handicap. Additionally, the primary source of resistance during certain exercise is the compressed nature of the weight-bearing ball. One means for adjusting the resistance is to alter the inflation of ball. Deflating the ball results in an increased resistance to rotation. Unfortunately, this results in a concomitant reduction in support to the user. As such, it is difficult to adjust the resistance to tailor it to the exercise and the user's needs. Finally, because the ball is not secured by any means, it is difficult to firmly stabilize an isolated part of the user's body, such as the user's feet or hands, so as to apply a significant amount of force to be exerted during the motion of the exercise. Thus, what is needed is an exercise apparatus that overcomes these limitations.